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Should I decide to chip my GTS R33 what should I expect from it? It has a huge exhaust and air filter to match. Is there a good dealer in the NorthEast?

Any comments??
 

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Andy,

You've not mentioned which type of GTS you have.

I think the reluctance to post a response to your query is basically that you don't need to chip your GTS. You do however need to account for the difference in fuel over here compared with Japan, and if you want more / better performance from the car, then the process to get reliable power is a tad more involved than a simple chip.

Check the board for info on Stu's R33GTS25T, it has had almost everything done that should be done to get reliable power from it, and the only thing holding it back from making even more power than what it already boasts is a set of larger injectors.

I'm running an APEXi PFC, with boost kit. This allows me to have the engine properly tuned, and to control the level of boost from the turbo. Together with the other mods I have, I believe it will be running near 275bhp, but this is as yet un-tested. (It could be more.)
 

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I think you also need to get an expert to see what ECU you have on the car now. Rod Bell found that mine had an after market chip on it that I didn`t even know about, it was actually running rich! which was a surprise, this meant I was able to up the boost and know the Fueling was still safe.

Go and see Rod Bell, you could do much worse.

Steve
 

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Doc!

Steve,

Glad to see Dr Bell sorted you motor mate!;)

We should call him doctor anyway the amount of sick cars he is treating & curing at the mo!
BTW Steve i would like a sniff round the motor some time soon!:D
Cheers

Stu
 

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Trev

Tis true but I wouldn’t recommend it - Rod was going up my pressure (not using this system though) and noticed it had a plastic wheel in the turbo and so any extra pressure would have resulted in a big bang pretty soon......

And no Im not happy about it :)
 

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A plastic wheel ! Is he pulling your leg or is this true?

How could a turbo use a plastic turbine?? Surely its got to be steel or ceramic or something? Why would anyone replace the standard turbo with plastic? I'm pretty sure Nissan didn't use plastic turbo internals on the R33 !

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Car of Origin: Nissan Skyline R33 GT25-T
Engine: RB25DET
Flange: Four bolt T3 style
Max. Power Rating: Approximately 185kW
Max. Boost: 1.2bar (17.4psi)
Cover Size: AR not identified
Comments: The RB25 turbocharger good for almost any mild six-cylinder application. Sparkling boost response in
the low-rpm range and a reasonably hard-hitting top end make this the most common upgrade found on
the RB20DET. It's highly recommended.
Cost: Being very difficult to get hold of makes them highly variable in price.
Rating: Five out of five
-----------------------------------------------------------------------------------
Car of Origin: Nissan Skyline R32, R33 GT-R
Engine: RB26DETT
Flange: Four-bolt, the same as the T25 series
Max. Power Rating: Approximately 150kW
Max. Boost: 1.3bar (18.8psi)
Cover Size: Exhaust 0.48 AR, compressor 0.60 AR
Comments: They are really only good for use on stock GT-R engines due to their relatively small exhaust housing.
For some reason, they seem to be able to handle more boost before turbine failure.
Cost: Anything with a GT-R part number is expensive!
Rating: Two out of five
------------------------------------------------------------------------------------

Trev
 

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No there was a plaggy part put in for a few months, turbo kicks in a bit quicker but the thing cant be boosted.....

I can have it converted over to all steel but then its going down the route of new intercooler oil cooler etc etc and could save that for a R34 GTS - I like sliding I do...
 

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Trevor said:
A plastic wheel ! Is he pulling your leg or is this true?

How could a turbo use a plastic turbine?? Surely its got to be steel or ceramic or something? Why would anyone replace the standard turbo with plastic? I'm pretty sure Nissan didn't use plastic turbo internals on the R33 !



Trev
Fraid so...... It uses a Ceramic hot wheel and a composite (read plastic) cold wheel, with a roller bearing core.

The hot wheel (turbine) is prone to flying off down the exhaust if the rpm of the turbo goes too high. Higher turbo rpm is usually associated with higher boost, as you would imagine.
However, if you're running a more efficient intercooler and piping, you can lose some of the losses - i.e. std IC and piping, runing turbo at say 1 bar but you anly see 0.7 bar at the manifold - this being where you read boost from. With a FMIC and proper piping the losses should hopefully drop so that you still see say 0.85 bar at the manifold when running the turbo at 1 bar.
So, if you are running 1 bar of boost you are always gonna be running the turbo at more than that, cos of the losses in the piping and cooler.
My point is, that if you have a FMIC you can in theory get away with slightly higher boost before the hot wheel goes bye bye....

On the subject of the plastic cold wheel, Ive heard that at high boost, the blades "curl" so that the boost is not as not as much as it would be if the cold wheel was steel.....
 

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RB25DET & RB26DETT BOOST MAX'S

I've asked this before but I'll ask it again...

What can a RB25DET engine take 'reliably' in the way of boost pressure?

I can now say with semi-confidence that boost at standard level on the R34 GTT has a max of 0.7 bar (10 psi). Anyone disagree?
On the R34 GTR the max is up a little to (12 psi), true?

I believe that the GTT matches the 320 bhp level of the GTR when its boost is raised to that of the GTR and its rear HUGELY RESTRICTIVE exhaust is replaced.

NEO TIMING (Nissans answer to Honda's VTEC)
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I've been told a rumour that the engine in the GTT is actually a more advanced version than is in the GTR :) and apparently they held the GTR back at launch to try to add NEO valve timing to the RB26DETT. They ran out of time :(

Nissan wanted the same style of valve technology as Honda's VTEC in there but they couldn't hold back the GTR any longer. It is believed that the new R35 will incorporate the next generation of Nissan's NEO valve timing technology. On the GTT the NEO timing of the cams can apparently be reprogrammed to give a higher (harder tuned) edge to the upper revs to effectively give 'free' uprated cams. Not sure how many tuners actually would have a clue about how to do this tho :(

Back to boost... Will raising the boost to 1.1 (16 psi) bar break things on the R34 GTT, with the RB25DET & NEO valve timing ? I know for sure it DOES NOT have probs in the short term. As always more regular oil changes are the best way for any upped boost engine.

I was told that the RB25DET (even in the R33) can take a max of 1.2 bar (17.4 psi) before it goes all Pete Tong. The RB26DETT is supposed to be able to take 1.3 bar (18.8 psi).

Anyone with a GTT (with std turbo's & IC) running 1.2 bar boost?
Anyone with a GTR (with std turbo's & IC) running 1.3 bar boost?
 
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